A man carries a giant Russian flag during a rally in Simferopol, Crimea. (David Mdzinarishvili/Reuters)

This week, Russian President Vladimir Putin pulled off a rigged referendum in which an overwhelming majority of Crimean voters chose union with the Russian Federation. But his victory is far from complete. The West retains a powerful card to play: mobilizing international opposition to deny Russia the international legitimacy it seeks for this naked power play. U.S. and European leaders have roundly condemned the referendum, citing international law. It would be wiser, however, for the West to shift the terms of the debate away from the legal merits of Russian conduct, and to focus instead on the illegitimacy of Russia’s annexation of Crimea and Moscow’s clear aspirations to expand its territory.

To date, the global debate over Russia’s intervention in Ukraine has been framed primarily in legal terms, but this is devolving into an exchange of accusations and messy interpretations of historical precedents. Indignant Western governments condemn Russian’s conduct and Crimea’s secession as a blatant “violation of international law.” Moscow, meanwhile, claims that it is affording the inhabitants of Crimea their inherent right to national self-determination “in full compliance with international law.” Russia has also accused the West of hypocrisy, invoking the precedent of Kosovo—which unilaterally declared its independence from Serbia in 2008, to the fury of Belgrade and Moscow but the vigorous applause of the United States and many European countries. Moscow notes that the International Court of Justice in July 2010 subsequently judged that Kosovo’s declaration of independence was legal.

Whatever the legality, Russia will find it even more difficult to sell the Crimean secession as legitimate.

The West has returned fire, noting that Crimea already enjoyed considerable autonomy in Ukraine, like several regions in Russia, but that Moscow had brutally repressed independence movements within its own territories, including in Chechnya and Ingushetia. Moreover, the West counters, the Kosovo referendum occurred in the context of a UN peace operation, eight years after a massive campaign of ethnic cleansing at the hands of Serbia. In the case of Ukraine, it is occurring in the presence of Russian military troops occupying Crimea, and with no evidence of any Ukrainian campaign of oppression against Crimea’s Russians.

This argument over the legality of Crimean secession has clearly proved a fruitless distraction. International law is flexible on the question of whether self-determination includes the right to secede. It is not a recognized “right,” but nor is it seen as necessarily “illegal.” Given the vulnerability of many states to secessionist movements, the general international preference has been to offer increased autonomy to ethnic minority enclaves, rather than independence. Secession, when it occurs, is expected to be a peaceful outcome of protracted negotiations both with the national government and the international community. In Crimea, of course, neither condition was satisfied. Farcically, the referendum was announced only 10 days before it was to occur, and neither of the two options on the ballot included the status quo.

And though the vote patently violated Ukraine’s own constitution (Article 73 of which requires a referendum of the entire country before its territory is altered), secessionists have rarely bothered to consult with the mother country before acting—further undercutting legal arguments. This is true both for successful secessions (e.g., the United States against Great Britain after 1776) and unsuccessful ones (e.g., the Biafran campaign against the state of Nigeria). The “velvet divorce” allowing the secession of Slovakia from Czechoslovakia in 1993 is the exception rather than the rule here.

Whatever the legality, Russia will find it even more difficult to sell the Crimean secession as legitimate. Despite attempts to liken it to Kosovo, (which 106 countries have recognized), the Crimean situation is more reminiscent of the Turkish Republic of Northern Cyprus, whose declaration of independence in 1983 has been recognized by only one nation: Turkey itself.

As I noted in a previous post, Crimea’s secession sets a terrible precedent. Hundreds of minority populations around the world might in principle insist on secession, throwing existing borders into chaos. Not for nothing did Woodrow Wilson’s Secretary of State Robert Lansing bemoan that the principle of national self-determination advanced by his president was “loaded with dynamite.”

Moreover, Russia’s aspirations are not limited to Crimea, and its successful annexation could clear a path for the Kremlin to seek to regain de-facto sovereignty over territories in the former Soviet Union with large Russian minority populations, under the pretext of protecting “oppressed” compatriots. We have seen this movie before, most obviously in Georgia. In 2008, the Russian military intervened to assist two breakaway republics, Abkhazia and South Ossetia. In the aftermath of that intervention, Moscow pledged to remove its troops. They remain there today. Or consider Moldova, where Moscow has for more than two decades supported the statelet of Transdniester, allowing it to become a veritable Walmart of arms trafficking.

But in this case, the scale of Russian audacity is even more alarming. Dismembering portions of tiny Georgia (population 4.5 million) and Moldova (3.5 million) was outrageous but of limited geopolitical significance. Doing the same to Ukraine—population 46 million—is another thing. It suggests that Putin is determined to expand Moscow’s effective control, formal or informal, over as much of the Russian-speaking “near abroad” as he can. That this impulse may be driven less by overconfidence than desperation is of little comfort. Historically, the world has had as much to fear from anxious powers in decline than rising ones eager to sow their oats. Consider the role that miscalculations by Putin’s Romanov predecessors, along with the aging Hapsburg dynasty, played in the outbreak of the Great War 100 years ago this coming August.

Dismembering Ukraine would enter the history books alongside the partition of Poland as a naked exercise in power politics.

Putin’s actions are unlikely to trigger another great power war. The United States and the European Union are already treating the annexation of the Crimea—a territory of only 2.3 million and a strategically and historically important part of Russia—as a fait accompli, But unless the West can make Putin feel the pain of his audacity, his irredentist ambitions are likely to grow. The most obvious target is the large Russian-majority population in eastern Ukraine, including the cities of Luhansk and Kharkiv. The resulting dismemberment of Ukraine, if allowed to proceed, would enter the history books alongside the partition of Poland as a naked exercise in power politics.

But Ukraine is not the only country of concern. Commentators have expressed worries about the Baltic nations of Estonia, Latvia, and Lithuania, given their sizable Russian minorities. In 2007, the mere act of dismantling a Soviet-era statue of Lenin in the center of Tallin led to a massive cyberattack on Estonian government ministries, apparently orchestrated from Russia. At the same time, Moscow is likely to avoid any direct military confrontation with the Baltic states—each of which is a NATO member—to avoid triggering a third world war.

More realistic targets for incorporation into an expanded Russian Federation, beyond Ukraine, are Belarus and, potentially, portions of Kazakhstan. The former is already Moscow’s most reliable client state, suggesting there is no hurry to absorb it officially. The latter could become a target, depending on whether the government of Nursultan Nazarbayev toes a Russian line within Moscow’s Eurasian Union or adopts a more independent course, including overtures to China.

Russia’s annexation of Crimea—which holds only 4 percent of Ukraine’s population—will not by itself significantly alter the balance of power in Eurasia. But it does establish a worrisome precedent that other powers—great and not-so-great—may seek to emulate. Beyond depriving Putin of recognition of his spoils, the West needs to send a powerful message about the wages of “sin”—in this case, unilaterally challenging the sanctity of borders. Targeting a few senior Russian officials for sanction should be only the beginning. And the Obama administration and international allies should stop citing international law and instead adopt more aggressive rhetoric noting that Russian expansionist aspirations are illegitimate and threaten peace on the continent.